


Rules of Engagement

by Adenil



Category: Star Trek, Star Trek: Alternate Original Series (Movies)
Genre: Actually More Like Relationship Dictation, Amazing sex, Anal Fingering, Bad Sex, But They Get Over That, Dirty Talk, Humor, M/M, Non-Human Genitalia, Office Sex, Plot What Plot/Porn Without Plot, Relationship Negotiation, Rimming, Telling Someone Not to Do Something is the Best Way to Ensure They Do It, Vulcan Culture, Vulcan Kisses, Weird Vulcan Things
Language: English
Status: Completed
Published: 2016-08-30
Updated: 2016-08-30
Packaged: 2018-08-11 23:02:11
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 7,052
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/7910968
Author URL: https://archiveofourown.org/users/Adenil/pseuds/Adenil
Summary: <blockquote class="userstuff">
              <p>Spock is totally fine to have sex with Leonard, they just have to establish a few (hundred) ground rules first.</p>
            </blockquote>





	Rules of Engagement

**Author's Note:**

> I should be working on What Keeps Us Alive, but instead here's some porn! <3 Love you all.
> 
> Edit to add: The lovely [Tilldeathpartsus](http://archiveofourown.org/users/Tilldeathpartsus) has translated this into Chinese [here](http://tilldeathpartsus.lofter.com/post/1e0fbd4f_e4eb21d). Thanks!

_nulla_

 

His quarters were dim and dark and he was nursing a cup of coffee, a headache, and a journal article about gene splicing when his door chimed at him. Leonard didn’t even look up from the dataPADD.

“Come in.”

He expected Jim, but wasn’t too surprised when Spock entered carrying a dataPADD of his own and three small datadiscs. Spock nodded to him the way one nods to a passing acquaintance in the hall. “Doctor.”

Leonard raised an eyebrow at him. “Spock. To what do I owe the pleasure?”

“I wish to continue the discussion we began three-point-seven standard weeks ago.”

Leonard didn’t have to think too hard--he remembered that little chat with burning embarrassment. It had started bad, with Leonard jokingly (hopefully?) mentioning that Jim said they fought like an old married couple, and it had gotten worse when Spock had declared point-blank that they could not fight in such a way because they were not bonded and never would be. Well, there had been a little fight (really just a little one, with a very tiny amount of yelling and carrying-on and swearing on Leonard’s part and an equally infinitesimal amount of eyebrow waggling on Spock’s part) and at some point Leonard had basically confessed the fact that he wanted in Spock’s pants, to which Spock had gone as tight-lipped as a clam and declared he needed to meditate.

The next day Spock had acted totally normal around him, and so Leonard decided to ignore the whole thing as well. It was for the best.

Only now Spock was dragging it all back up. Leonard gave a delayed wince.

“Spock, that’s really not necessary.”

“I believe it is, Doctor. You stated that you would not be averse to engaging in sexual intercourse with me.” Leonard winced again. That was a pretty white-washed paraphrasing of what he’d actually screamed at the Vulcan. “After consideration, I must inform you that I would also find the addition of a sexual element to our relationship to be acceptable.”

Leonard gaped at him. Spock just stared back, implacable. Leonard closed his mouth with a snap and then said, “Oh?” as nonchalantly as possible.

“Indeed. However, there are rules.”

“Rules?” Leonard asked faintly.

Spock held up his dataPADD and discs. “Rules. I have compiled them for ease of reading.” He set them down on Leonard’s desk. “Please examine them and report back at your earliest convenience.”

“Wh--I, uh, okay?” He winced. Smooth, Leonard. Very smooth.

Spock nodded at him. “Good day, Doctor.”

He turned smartly on his heel and left before Leonard could find his scattered wits. The door snicked shut behind him.

Leonard binked. Blinked again. He blinked a third time and set aside the article he had been reading and picked up Spock’s PADD and turned it on.

Report on Required Rules of Engagement for Non-Pair Bonded Vulcan Sexual Relations  
Table of Contents

> Introduction pp ii-xlviii  
>  One: Background Information on the Teachings of Surak, Emphasis on the Logic of Sexual Intercourse in Non-Bonded Pairs pp 1-59  
>  Two: Contemporary Interpretations of the Teachings of Surak, Emphasis on the Logic of Sexual Intercourse in Non-Bonded Pairs pp 60-167  
>  Three: List of Rules and Explanations for Engaging in Sexual Intercourse (Disallowed Actions) pp 168-555  
>  Four: List of Rules and Explanations for Engaging in Sexual Intercourse (Allowed Actions) pp 556-560  
>  Appendix A: Definitions of Terminology pp 561-600  
>  Appendix B: Figures pp 601-617  
>  Bibliography pp 618-639

Leonard decided he was going to need something a lot stronger than coffee, and he broke out a bottle of whisky he’d been saving for a dire occasion indeed.

I

_0027: Non-bonded pairs may not touch any part of the hand or fingers above the navicular bone during sexual intercourse. Humans may use hands to grasp, hold, or maneuver the partner, provided they do not touch the Vulcan partner above the navicular bone._

“So is it the skin-to-skin contact, or what?”

Leonard hadn’t wanted to hold someone’s hand so damned much since he was a teenager. He had never really noticed Spock’s hands before. Sure, they were nice to look at. He had very fine, long fingers and he kept his nails well-manicured and his skin always looked buttery-soft but also hard where his callouses were and he was always grasping things and rubbing his thumb over his bottom lip and tapping his strong fingers together in contemplation and--okay, so maybe Leonard had noticed. But now he was noticing even _more_.

“Perhaps you should read my report in more detail. It is explained that hands and fingers are considered erogenous zones by Vulcans, in part because touch is necessary to initiate a mind-meld with most species. Touching hands is therefore indicative of attempting a meld.”

“But it’s also sexy?”

Spock stared at him. “I would perhaps phrase it differently, but in essence you are correct.”

Leonard sat back on his couch and frowned more intently at Spock’s hands. An erogenous zone. That gave him so many ideas. He could imagine hand massages until late at night, until Spock was mewling under him, and then carefully taking just the tip of his forefinger into his mouth. Dancing his tongue against the pad, calloused over from button-pressing and hard work. He could suckle it as Spock went cross-eyed, let his own mouth hang open, hips twitching with each lick of his tongue. “...What if you wore gloves?”

Spock considered. “That is not advisable.”

Leonard still couldn’t look away. He wondered how close he could get to the navicular bone before Spock started getting nervous.

II

_0058: Given the human social constructions around the act of touching lips, “kissing” between non-bonded pairs where one partner is human is forbidden during sexual intercourse. This includes: licking the partner’s lips, biting the partner’s lips, touching the partner’s lips with fingers, and attempting to open the partner’s mouth with lips, tongue, or fingers._

He had never wanted to make out with someone so hard in his _life_.

“What if I kiss you other places?”

“Please elaborate.”

“Like…” He scooted a little closer so he could reach out and touch Spock. “What about the elbow?” He placed his fingers there.

Spock nodded. “Acceptable.”

“The face?” He touched Spock’s high cheekbone.

“Acceptable.”

“Chin?”

“Acceptable.”

“Hell even all around your mouth is okay…” He trailed his fingers in a tight ellipse around the forbidden zone. “But the lips are right out?”

“Correct. As are hands.”

Leonard frowned hard at Spock. “Can I lick you? Spock, I really want to lick you.”

Spock frowned with his eyebrows. “That is not logical.”

“Yeah.” Leonard sighed. “It’s really not. So, uh, that’s a no, then?”

It was.

III

_0188: Non-bonded pairs wishing to engage in sexual intercourse must choose one partner who will be penetrated at each subsequent encounter. In the case where one partner is a human male and the other is a Vulcan male, it is recommended that the Vulcan be the penetrating partner._

“Well how is that logical!?”

“Doctor, you are a male.” At that, Leonard puffed up, even more annoyed. “And as such your body is not able to be penetrated comfortably without mechanical assistance. Nor is mine. However, my penis produces a variety of fluids during arousal that will make penetration more bearable. This will be the most comfortable and pleasant experience for both of us.”

Leonard shifted in his seat. He liked getting penetrated just fine, he just didn’t like it being _prescribed_ to him. “...Because of the no-touching thing we can’t actually finger each other, is that it?”

“Indeed.”

“Well, you could always finger yourself. What about that?”

Spock went a little misty-eyed, and Leonard counted that as a win even though Spock eventually said, “That is not logical.”

IV

_0189: Sexual intercourse between non-bonded pairs shall involve the penetrated partner kneeling and supporting their weight with hands. The penetrating partner shall enter from behind (see fig. 17)._

“It’s illogical to _look_ at each other?”

“The most physically comfortable position for male-male intercourse is—”

“Yes, yes, I know. I am a doctor. But what if we want to switch it up?” God, he could imagine it now. Spock splayed out on the bed, all pale-green lines, his hands clutching at the headboard above him ( _don’t touch_ , Leonard would whisper _, you know you aren’t allowed to touch_ ) and he would slurp all around Spock’s weeping cock, licking at him and getting his slick to pour out of him and then he would shimmy up, holding Spock down with both hands, and he would sink so, so slowly onto that curved erection as Spock quivered and bit at his lip, and he would accept each thick inch of Spock until he thought he might blow apart at the seams, and he would rock back and lift up and slam down, pleasuring himself on Spock, using Spock like a toy. “What if, uh,” he stumbled over his own words. “What if I get a crick in my back?”

“Then we will engage in sexual intercourse at another time.”

“What if I want to fuck you?” he asked, annoyed.

“That is possible. We simply must make the determination before our first engagement, as subsequent attempts at intercourse will be modeled in the same way.”

“That is the most illogical thing I’ve ever—” He stopped himself at Spock’s look. “Fine. You do me, then. Since you’re so damned excited about it.”

V

_0212: For non-bonded pairs, arrival at tumescence must be accomplished in isolation. After tumescence has been reached sexual intercourse may begin._

“I can’t even watch you masturbate!?”

“Doctor, masturbation is an illogical waste of energy. I would touch myself with the intended purpose of achieving an erection suitable to penetrate you, not to achieve climax while in isolation.”

Fuck, that sounded hot. “We could do it in bed together,” he tried to bargain. “I promise I wouldn’t touch you with either of my illogical hands. I just want to watch you, Spock.”

Spock considered. “...My reading of the book of Surak, day four, does not allow for that.”

Leonard had never wanted to punch a dead guy so much.

VI

 _0600: Further disallowed sex acts between non-bonded pairs include: fellatio or oral stimulation of the sex organ..._  
_0601: ...manual stimulation…_  
_0602: ...intercrural sex…_  
_0603: ...rubbing the sexual organ against the body of the partner for the purposes of sexual gratification…_  
_0604: ...sexual intercourse without achieving full nudity…_  
_0605: ...stimulation of the ear or ears…_ _  
_ 0606: _...emitting sounds which are intended to demonstrate pleasure or to inspire pleasure in the partner_ …

“Wait a goddamned second. I can’t _moan_?”

“There are multiple interpretations of this edict. Some believe that this rule is intended to prevent what humans call ‘dirty talk.’ However, a strict reading of Surak’s teachings also includes other excited exhalations.”

“And of course, you have a strict reading of Surak.” When Spock nodded, Leonard sighed for what felt like the millionth time. “Figures.”

VII

 _0988: Non-bonded pairs may not remain in physical contact after orgasm for both partners has been achieved_.

“I can’t cuddle with you?” Leonard asked. He looked up at Spock and felt wetness in his eyes.

Spock drew back, looking deeply disturbed at the sight of Leonard nearly crying. “No.”

VIII

_1001: For non-bonded pairs, NO sex acts may be performed while conducting normal work duties._

He started to move on before he noticed Spock looking at him intently. “What?” he asked.

Spock raised an eyebrow. “You do not intend to argue with me?”

“Well, of course I’m not going to fuck you at work, Spock. Sorry, of course _you_ aren’t going to fuck _me_. Jesus, I have some decency.”

Spock nodded, and Leonard told himself he was imagining the look of disappointment. Anyway, they were done going through the rules now. Leonard set the PADD aside and scrubbed at his face.

“Thank you for meeting with me and clarifying a few things,” he said after a moment. “I think I need some time to think about it.”

Spock nodded again and stood. “Then I shall take my leave of you. Good day, Doctor.”

Leonard watched him go, already kicking himself. He knew he would say yes to all of Spock’s ridiculous demands, but he wanted to give Spock the illusion that he was seriously thinking about it. He wanted Spock to be the one sweating for a change.

He had a very vindictive jerk-off session that night. Leonard smirked when he finally came, muttering, “Illogical waste of energy my ass.”

IX

Leonard managed to make Spock sweat for almost twenty-four hours before he called him into his quarters.

He stood nervously in the center of his room. “So I’ll, uh, get naked then.” He bit his lip. “You’re sure it’s illogical for us to help each other with that?”

Spock nodded. “Rule 0015 details this clearly. I will use your bathing room. I will return in six-point-one minutes, prepared to penetrate you.”

“Uh.” He watched Spock go. “Okay.”

He took off his uniform and then stood there, looking at the bed and dithering over what to do next. After a minute he pulled up Figure 17 and studied it before crawling onto the bed, face down. He spread his legs and let his cock hang down between them. He stared at it. It seemed to stare back, the sort of general _what the fuck have you gotten yourself into, McCoy?_ kind of stare.

He started to touch himself.

Despite the oppressive awkwardness of the situation, imagining Spock in the other room stroking himself was an amazing turn-on. It didn’t take long for him to begin filling out in his hand, but he was still only about half-hard when Spock came back into the room stunningly naked.

Leonard stared at him. Spock inclined his head and walked briskly across floor. His shiny penis was fully erect, jutting out of his sheath and looking positively dangerous. Leonard drank in the sight of him: his lean legs, long arms, straight fingers, his slight little hips. His chest was covered with dark hair that went in all different directions. His hair was still perfectly coiffed. His face was impassive. Leonard quickly looked away as Spock knelt on the bed behind him.

“I will now begin penetrating you.”

Spock didn’t touch him--of course not, that was rule number 27, and one of the most important rules at that. He could feel the wet, blunt head of Spock’s penis at his entrance and he let out a breath. He wished he could bury his head in his arms, but he had to keep them ramrod straight in accordance with Figure 17. He stared at his spread fingers on the bedspread as Spock pressed against him.

His cock gave a confused throb as Spock twirled around his ass, spreading his own version of precome all over the place and getting Leonard nice and wet. There really was an awful lot of slick, and it didn’t take long for Spock to press more firmly and, fuck, _ouch_. Logic was such a bitch not to give them a little wiggle room for fingering. Leonard bore down as best he could--he could do this, he told himself firmly, blinking away the automatic tears of pain that welled up--and Spock pushed, leaned, and then he was inside.

A shudder ran through Leonard as Spock slipped into him. God, it was horrible and erotic, the only point of contact Spock’s penis slowly filling him. It took every ounce of strength not to moan as his body stretched out to accommodate the intrusion. Eventually Spock bottomed out and held very still. Leonard could practically hear Spock counting in his head, in accordance with Rule 195. He wanted to push back against Spock so desperately, but he couldn’t. If he moved even slightly Spock would be well within his rights to call this off, and Leonard could _not_ handle that.

Then, when the requisite time had elapsed, Spock began to thrust.

It was a maddening, steady thrusting. Leonard knew that each thrust cycle took 2.4 seconds to complete, because those were the requirements of Rule 201. It was just slightly too slow to be rough, and slightly too fast to be languid. And Spock kept it so steady that Leonard had no illusion that his partner was desperately struggling for control. No, Spock could probably do this all day. And he would have to do it for a while, because this was the only way for Leonard to come.

He chewed at his own lip. Yeah, he could probably come like this. It would be awkward as hell without being able to touch himself, but he could still come. Spock’s penis seemed to be just the right shape to hit his prostate on each withdrawal, starting that slow burn inside of him. That was, that was good, he told himself. He looked down again and saw his cock, angry red and rocking between his legs. He could see Spock’s muscled thighs just beyond, moving in steady rhythm. He really, desperately, wanted to rub himself off on one of those legs. He wanted to kick Spock off and straddle his thigh, rub until his cock was raw from friction, rub until he was leaking precome and shuddering, shuddering, rub until he came all over Spock’s surprised face and he could see Spock licking off the come, intrigued, wanting more of that taste—

He moaned.

Leonard quickly bit down on the sound, but it was too late. Spock had stopped moving.

“Doctor,” Spock said, sounding way too fucking calm for someone who had his penis inside another guy. “Please recall the rule numbered 0606.”

“I remember,” Leonard said. He tried to keep his voice level, figuring that was what Spock would want. “I’m sorry it just...slipped out. I’ll do better.”

Spock didn’t move for a prolonged moment. Leonard thought surely Spock was going to leave. But, eventually he moved forward again, driving against Leonard’s prostate and making his legs quiver involuntarily.

After that, he tried not to think about it so much. He let his mind focus on Spock’s even breathing and the gentle slapping of Spock’s hips against the curve of his ass. He watched his hard cock swing back and forth like a pendulum and he thought that the whole experience was weirdly meditative. He felt detached--Leonard could sense the building orgasm within himself, but it was still a surprise when it came. It felt as if it were happening to someone else.

He spurted out on the bed sheets, squeezing every muscle in his body. He thought he felt Spock falter, but it was probably his heady imagination. Spock lasted precisely five more thrusts before apparently orgasming as well. Leonard had to take his word for it, since Vulcans had a dry orgasm.

Spock pulled out and knelt back. Leonard hastily curled up into a little ball and considered his life choices.

“So that was—” Jesus, he was shaking. He tried to relax. “Good? That was good? Was it alright for you? I thought it was fine, good, good and fine. It was all good.”

Spock stared at him flatly. “All parameters were met,” he said after a moment.

“Except for that one moan. Sorry about that.”

Spock continued to stare at him.

Leonard internally panicked. “Next time I’ll do better, I promise,” he said. He tried to smile, but maybe Spock wouldn’t like that after sex, so he quickly squashed the motion. “Do you want to do this again sometime?”

“...I will contact you,” Spock said. He still looked totally emotionless, as opposed to just extremely emotionless like he normally looked.

“Okay.” Leonard watched as Spock rose from the bed and walked into the bathroom. He emerged thirty seconds later totally dressed again in his uniform and nodded at Leonard.

“Good day, Doctor.”

And he left.

X

Leonard managed to go a whole week telling himself that he was a strong, independent doctor who didn’t need no Vulcan, but he knew he wouldn’t be able to keep it up. He took himself in hand nightly to the images of Spock, naked, walking across his room. Spock with his cock hard and ready. Spock sliding into him. Spock’s soft breathing noises. Spock’s elegant fingers perpetually out of reach.

As distant and reserved as the sex had been, he craved more of it. Of course, he knew he wouldn’t get it since Spock had given him the Vulcan equivalent of _don’t call me, I’ll call you_.

He sat at his desk in his office, mentally scouring his memory of that night for where he may have gone wrong. He had only had that one slip up--that one little moan. And Spock had seemed understanding. Anyway, it made sense that a human would be bad at following all those rules so suddenly. He had followed the other thousand just fine! Was he just a bad lay? Was Spock not aroused by him anymore? Maybe Spock was a love ‘em and leave ‘em kind of guy. Just like a man to take what he wanted and then leave Leonard painfully alone.

He was still anguishing over all of his unanswered questions when his office door slid open and Spock walked in.

“Mr. Spock,” he said, surprised. “I didn’t expect to see you. Are you sick?”

Spock opened his mouth, closed it, and then opened it again to say, “Computer, set room to privacy mode, to be released only by voice identification match from First Officer or Chief Medical Officer.”

“Acknowledged,” said the computer. “Privacy mode engaged.”

The sound of the door locking was ominous.

“I have made a terrible mistake.”

Leonard jumped up and leaned over the desk, worried. “Spock, what’s wrong?”

Spock rounded his desk in four quick strides and crowded into his space. Spock grabbed the front of his shirt and yanked him in, kissing the living daylights out of him.

Leonard felt his eyes go wide as Spock kissed him. What the hell was this? A test of some kind? Seeing if he would break the rules? But Spock seemed well and truly desperate as he tried to work his way into Leonard’s mouth, licking at him and nipping at him and just basically stomping all over rule 58. Surprised, Leonard let his mouth fall open and Spock made a needy sound and thrust his tongue inside and, okay. Spock was not the greatest kisser (which made sense, since this was potentially his first kiss) but something about his desperation and the way he was all teeth and zero finesse turned Leonard on so fast his legs wobbled.

He kissed Spock back twice as hard, taking ownership over their sloppy make out and trying to teach Spock a thing or two. Spock was a very willing student. He opened his mouth to Leonard and made another one of his breathy, needy sounds as Leonard explored him, traced his teeth and tongue and danced across the roof of his mouth, lapped at him, consumed the taste of strawberries (strawberries? strawberries.) with every passing motion. Spock was quivering and shuddering and his mouth was slick and hot and Leonard wasted no time before grabbing Spock’s hand and tugging at his fingers.

Spock shuddered again and let out a long, low moan that Leonard happily swallowed. He kept touching Spock’s hand, far above the navicular bone. He rolled Spock’s hand in his, tracing the rough callouses with one nail, then trailing his dancing fingers down to press, rough and hard and steady, at Spock’s palm. Spock jerked beneath him and his hips stuttered and Leonard couldn’t take it anymore so he shoved Spock backwards onto his desk.

PADDs and styluses and a coffee mug all went flying. The mug shattered. Leonard insinuated himself between Spock’s legs and pulled back for a gasping breath. Spock writhed beneath him, touching Leonard’s hand desperately and although hands weren’t really an erogenous zone for humans, seeing Spock out of his fucking mind like that was certainly arousing enough.

“Do you like that?” he asked.

Spock stared at his hand like it was performing an Orion erotic dance and said, “I have always admired your hands.” He pulled it up and pressed his lips to Leonard’s fingers. His eyes fluttered shut. “Perfect.”

Leonard gave the finger to Rule 58 as he touched Spock’s lips all over. Spock let his mouth fall open and Leonard took advantage, sliding his two forefingers over the quivering tongue as Spock suckled at him. He bent low over Spock and kissed at the Vulcan’s collar before throwing caution to the wind and licking a swath up the cord of his neck to his ear.

Spock shivered and said something around Leonard’s fingers, and Leonard took that as permission to break Rule 605. He danced his tongue over the fine point of Spock’s ear then down, taking the lobe between his teeth and gently kneading. Spock shuddered under his touch and his hands fell to his pants.

Okay, this Leonard had to see. He pulled back to watch Spock--eyes closed in bliss, mouth smeared wet, breath coming in fast pants--suck at his fingers as he undid his own pants. Leonard had one free hand and helped him, and soon enough Spock was struggling to kick off his boots and then he was just in his blue shirt and Leonard was pretty sure there had been a rule in there about nipple play and how you really shouldn’t, but he thought _fuck that_ and shoved his free hand up Spock’s shirt.

Spock wrapped his bare legs around Leonard’s waist and began to rub. Leonard tried to line up so his clothed cock would rub up against Spock’s sheathed one, but the angle was awkward and anyway he was distracted by how Spock’s back arched as he lightly thumbed his nipple.

“Ooohnnn,” Spock said intelligently around his mouthful.

“Yeah, d’you like that?” Leonard asked. “Like my hands on you?” He bit his lip as Spock nodded furiously. “You ever done this to yourself?”

Spock hesitated, but then shook his head.

“Y’got two free hands. Use them here for me darlin’, will you? I want to touch your pretty cock.”

Spock shivered and pulled his shirt up so it bunched under his arms. His hands pressed at the flushed skin and his back arched again. God, he was so sensitive there. How could Spock not have explored his body like this? Let himself come undone under his own touch? Spock kept twirling his fingers over his nipples as he sucked hungrily at Leonard’s two fingers.

“Look at you, sucking so good,” Leonard praised. He cupped his hand over Spock’s slit as he did so, letting his middle finger slip in almost-accidental-like. “You’ve got such a pretty mouth, Spock. And I can tell you’re hungry for it. I bet you’d like to have my cock in your mouth, wouldn’t you?” At Spock’s desperate nod, Leonard chuckled. “Yeah, you’re sucking so good for me. Would you like a little reward? Hmm? Here you go, darlin’. Just for you.”

Spock’s eyes rolled back in his head as Leonard slid a third finger into his mouth. He was rocking wildly now, his knees bent almost to his chest to give Leonard enough room to maneuver in between his legs. He slid another finger inside that dripping slit and tickled at Spock’s cock. It took only a few, feather-light touches for Spock’s cock to unfurl, sliding out of his sheath and into the cool air of his office like a gift.

“God, look at you.” He closed his hand around Spock’s cock. Stroked once. “Sittin’ nice and hard in my hand. Do you like being all wet and hard for me, Spock?” The answer was a resounding positive. “Mmhmm, I know you do. I’m gonna keep stroking you like this ‘til you come, do you know that? Until you come right in my hand with your hips quivering and your body clenching all pretty like. Yeah, just like that. I’m gonna make you come right here and then we’re going to try something you'll find _fascinating_.”

Spock shuddered at the mere suggestion and danced his tongue between Leonard’s fingers. His eyes were closed again, his hands alternately stopping and starting on his chest as he fell deep into that pit of pleasure where focus on a single task became impossible. He stopped being able to suck properly and instead his mouth hung open, wet and filthy, as Leonard gently thrust his fingers in and out, a pantomime of a blow job. Leonard purred wet-hot-filthy praise into his pointed ear until he felt Spock twitch, and his hips lifted up, and he let out a strangled keen that shook Leonard right to the core.

“Good, darlin’, oh you did so good for me.” He stopped stroking, but kept his hand lightly holding Spock’s erection. As long as he held it, it wouldn’t retract, even as Spock came down from his orgasm. “I’m gonna lick you, Spock.”

Spock make an inquisitive sound as he drew his slick hand from Spock’s mouth. With two wet hands he took Spock by the hips and turned him over so his stomach was pressed hard against the plastic of the desk and his bottom was upturned in the air. Spock spread his still-shaking legs just like a proper “penetrated partner” and made another inquisitive sound.

“Will you fuck me, Leonard?”

Oh, and everything about that sentence was glorious, from the obscenity to the pleading tone, right down to the use of his name. He rubbed some of Spock’s spent slick against Spock’s tight little hole and murmured, “Sure enough. Just as soon as I get you ready.”

He knelt and pressed his face in, kissing all around at Spock’s tight ass (which he had noted so many times before, but not quite like _this_ ) and then he took his thumbs and spread Spock wide, opened him up, and dipped his tongue into the crevice and Spock _keened_.

“Leonard! Ohh…” He trailed off, muttering nonsense as Leonard licked at his hole and then pointed his tongue, diving into that tight ring of muscle that opened so willingly for him. “Leonard--it feels--oh, don’t stop.”

Leonard did not stop. He kept right on rimming Spock until the Vulcan was writhing under him, begging in clipped sentences that kept getting interrupted with moans and with Spock biting at his lip in desperation and with the clack of teeth and feral growls. Then he dipped his forefinger--with a generous helping of Spock’s slick--in alongside his tongue. He spread it around and around, toying with Spock now, stretching him out with one bent finger and one good and proper tongue-lashing.

When he slid a second finger in there was really no more room for his head, so he stood up and scissored his fingers as he kissed the back of Spock’s sweaty neck--and there was something to see. A Vulcan sweating. It tasted like sugar water. He licked at Spock and Spock twisted beneath him, tried to get his legs further apart as Leonard spread his slick around.

“I’ve gotta hand it to that Vulcan cock of yours,” Leonard murmured into his hair. “All this slick comes in mighty handy. I like the idea of you getting so turned on that your body knows it. That you can’t help but get all wet for me. Do you like that, Spock?”

“Like?” Spock sounded confused. He turned his head to one side and gazed, glassy-eyed, at the far wall.

Leonard laughed. “Yeah, you do.”

Spock was so tight and hot around his probing fingers. He tried to slip in a third and it was a struggle to point his fingers just right, to admire Spock’s eyes closing in discomfort and pleasure, to press _in_ until his three fingers were all the way inside and Spock’s hole was fluttering around the intrusion, swallowing at it.

“God, you’re so eager. Look at you.” He fucked Spock with those fingers. “Do you want me in you, darlin’? Is that what you want?”

“Yes,” Spock demanded, and his voice snapped in the middle. “Please, Leonard. I am ready now.”

Leonard smiled down at him. “No you aren’t, sweetheart. You’re still too tight to take me. Do you feel that?” He spread his fingers wide and drew them almost all the way out before plunging back in, and Spock jerked his hips forward and cried out. “We gotta get you to accept all ’a that. That’s a lot for you, darlin’. Maybe it’s too much for you to handle?”

“No,” Spock said instantly. “I can take it. Please, Leonard. I-I wish to face you when you penetrate me.”

Ooh, that did things to Leonard. Made his very-interested cock throb with desperation, with need. “Okay, I can do that for you. But I’m gonna need to get you a bit more wet first, okay?”

Spock shook his head. “I must to see you _now_.”

“All right,” Leonard said breathlessly. “All right, let’s roll you over.”

He slid his fingers from Spock and Spock flipped over in a flash, propping himself up on his elbows. His hair was askew and his eyes were gleaming heat and he surged upward to claim Leonard’s mouth again, and he did a much better job with this kiss. Leonard licked at him as long as he could stand it before pulling away reluctantly and slithering down to kneel between Spock’s legs again.

“Len--oh!”

Rule 600 could suck a big one, Leonard thought as he slurped at Spock’s cock, inhaling as much of his length as he could. Spock tasted wonderful, metallic and sweet, and he brought up his hand to gather a heaping palmful of slick. It really was pouring out of Spock now, and he got a nice amount that he used to slide three fingers back inside of Spock.

“Leonard,” Spock said, reduced to rather simple language. “Leonard, _oh_.” His hands came up to hold Leonard’s head, hesitant but encouraging. He tugged at Leonard’s hair and Leonard liked that, so he moaned, and Spock took the hint and tugged harder. “Leonard, I am going to, I am going to orgasm again.”

Leonard hummed. He quite enjoyed that idea. And the best part was he could keep right on sucking Spock as he came--and he did. Verily. As Spock curled around his head, powerful thighs closing over his ears, shuddering, shuddering, the muscles in his stomach clenching and unclenching and he _groaned_ and shivered and Leonard licked him and licked him and sucked him and Spock said, “Please, too much, please!”

He took pity on Spock. He pulled off with a wet slurp and stood up, fingerfucking Spock’s now-quite-loose hole with reckless abandon as he rose. “Undo my pants,” he said.

Spock obeyed with shaking hands that were still surprisingly deft. He pulled out Leonard’s cock and looked at it with open wonder, but Leonard didn’t give a fuck about wonder right then. He just leaned forward to rub his aching cock all over Spock’s slick erection, getting himself as wet as he could.

“Are you ready for me, darlin’?”

“Yes, yes.” Spock was still staring at him, and it was almost disconcerting, so Leonard pulled out his hand and lined himself up and _pushed_ and Spock’s eyes fluttered shut, his neck arched, and a little whisper escaped those pretty pressed-green lips. “ _Yes_.”

Spock was still tight, so tight, tighter than Leonard could have imagined, and he was glad that Spock had been the one to fuck him their first night, because the thought of hurting his partner--he shook it off, and kept pushing, sliding through Spock’s involuntary jolt of surprise, sliding through the way Spock didn’t know what he was doing and tried to close himself off.

“Here, darlin’ just relax. Just relax. I know you can do it. I know you can be so open for me. I know you can let me in, let me take you. Will you let me? God, you feel so good, so good around me.” And he had to close his eyes, too, as he bottomed out and the shear pleasure almost tipped him over the edge.

Spock grappled at him with both hands and tried to curl his long bare legs around Leonard, but Leonard caught him under the knees and instead pushed his legs up, up to his chest so Spock was folded in half, just lying there all delicate and open for him. And Spock gasped as he did it, tipped his head back and gulped as it allowed Leonard to slide in just that much deeper.

“D’you like it?” Leonard managed to ask.

Spock swallowed again, his throat clicking. “Please move. Please. Leonard, you must move.”

Leonard huffed out a laugh and leaned down to kiss Spock’s beautiful lips. “I’m moving. Don’t you worry, sweetheart. I’m moving.”

He did not really set a pace. He pulled out, out, until just the head of his cock was still barely holding on, and then slipped back in inch-by-bare-inch as Spock shuddered around him. Then he pulled out, paused, and thrust in hard enough to make Spock jump and nearly tear his shirt right off of him. He fucked Spock however he felt like: sometimes slow, languid, drawing it out until Spock was practically begging for it--other times fast, hard, furious, almost angry as Spock keened under him and tried desperately to move his hips back against him. And he kissed Spock. Kissed him opposite to his thrusts, so that when his cock was being gentle his tongue was being cruel, and vise versa.

“Touch yourself,” he demanded once, and Spock did.

Spock wrapped those long, calloused fingers around his own shaft and stroked himself. He made such a lovely sound as he did it, hand fisted and caught between their bodies, masturbating but not in isolation. Leonard loved it, and he had to pull back to see. To keep a close watch on whether Spock was doing it properly. He was.

He kept Spock’s knees folded as he stood straight and gazed down at Spock, watched Spock toss his head from side to side as he bit at his lip and fucked his own hand. Watched Spock work to impale himself again and again and again on Leonard’s hard cock. Watched Spock tense his legs as he drove himself towards climax. Watched Spock watch him back with burning brown eyes, sweat pooling over his lip.

“You’re so beautiful,” Leonard said. He could barely keep it together. “So beautiful like this, for me. God, Spock, I--I’m so happy I can do this with you.”

Spock seemed beyond words, but he nodded, hair flopping gently against his forehead. He made a sound low in his throat, like a question.

“Getting close?” Leonard asked. “You’re gonna make yourself come? That’s good, ooh that’s good Spock. I want you to make yourself come. Make yourself come just for me. You come and get all tight around me, yeah? Do you want that?”

Spock nodded and his fist picked up speed, a fast blur as he stripped his cock, the wet-slick slapping sounds loud and mingling with Spock’s desperate breathing and Leonard’s whispered words of encouragement and his occasional broken moan and the slap of Leonard’s balls against Spock’s ass and—

Spock arched and went tight around him and that was too much, way too fucking much, and Leonard hurled himself right over the edge in a tangle of limbs and emptied himself out into Spock’s waiting, willing, _writhing_ body and he felt like it would never end, the long tumble of his orgasm, tense and hurting and _ohsofucking good_. And when he collapsed, Spock curled around him, and together they fell to the floor, still connected.

He was tired for a long time, or maybe unconscious. He eventually became aware of Spock’s hands in his hair and on the back of his neck, Spock laying gentle kisses along the side of his face and the curved shell of his ear. Leonard turned to kiss Spock back and Spock opened his mouth so sweetly that Leonard nearly had his heart break in two, right there on the cold floor of his office.

“Beautiful,” he said when he pulled back. “God, Spock. You were amazing.”

Spock looked away, almost abashed. He was very open right then. “Thank you, Leonard. For indulging me.”

Leonard wiped a finger over Spock’s brow, straightening the eyebrow there. “Of course I’m going to indulge you, idiot.”

“How kind,” Spock said flatly, but there was a hint of humor.

Leonard really wanted to cuddle some more, but the cold floor was wreaking havoc on his knees. Spock seemed fine with it, so Leonard was the one to break the ice by starting to wiggle away. He fell from Spock’s body and Spock disentangled his limbs, pulling a face when he tried to straighten his leg. Spock quickly hid the reaction.

“That was mighty fine,” Leonard said again as he fastened his pants and watched Spock hunt around for his right boot.

“Yes,” Spock said after a moment. “Perhaps we could...do it again sometime?”

He looked incredibly nervous, and so Leonard took instant pity on him. Instead of teasing him and stringing him along, he took Spock’s face in his hands and kissed him soundly. Then he took Spock’s hand and kissed that, too, for good measure.

“Spock,” he said sternly once he was done with all the kissing, which had inexplicably taken a lot longer than he’d planned. “Not only are we going to do this again, but the first thing we are doing tonight is to go back to my quarters to get your dumb rules, and then we are going to break every single one in numerical order. One every night. For the next one-thousand-and-one nights. And then we will start over and find some new ways of breaking the rules. How does that sound?”

Spock had that misty-eyed, contemplative look in his eyes again, like he was picturing with pinpoint scientific accuracy a million different sexual positions. “That sounds acceptable, Leonard.”

Leonard chuckled. “God, you’re a pain in the ass.”

Spock arched an eyebrow. “Is that a promise?”

It was.


End file.
